IL109141A - Back-flushable filters - Google Patents

Abstract

A filter operable in either a filtering mode or in a flushing mode, comprising: a housing (2) including a cylindrical filter chamber (7), and further including a fluid inlet (3), a fluid outlet (4), and a flushing outlet (5) communicating with said filter chamber; a cylindrical filter body (8) disposed within said filter chamber and having an upstream face communicating with said fluid inlet and a downstream face communicating with said fluid outlet; a plurality of partitions (10) defining, with the housing and upstream face of the filter body, a plurality of axially-extending, circumferentially-spaced filter compartments (11) each communicating with an axially-extending section of the filter body; blocking means (12) for blocking communication between said fluid inlet and at least one filter compartment, while unblocking each remaining filter compartment by permitting communication with said fluid inlet; a flushing pathway (16) between each blocked filter compartment and said flushing outlet; and a valve (17) in said flushing pathway movable either: (a) to a closed position during the normal filtering mode, wherein a filtering operation is performed in each unblocked filter compartment to filter the fluid flowing from the fluid inlet to the fluid outlet, or (b) to an open position during the flushing mode, wherein the same filtering operation is performed in each unblocked filter compartment, and a flushing operation is performed to flush, via the flushing outlet, in each blocked filter compartment; said blocking means and filter body being rotatable relative to each other to enable said blocking means to be aligned with, and thereby to perform a flushing operation with respect to, all the axially-extending sections of the filter body.